Hi,
ChromeDriver isn’t Chrome itself. If you’re using a Render Native Environment, Chrome isn’t installed by default, so you’ll need to install it yourself.
As you mentioned, there are plenty of posts that cover installing Chrome on a Native Environment. The starting point is usually a script like https://gist.github.com/BigAlRender/41f4c4d87df3e25770e3db8db728443e
Alan